1. Field of the Invention
The invention is in the field of broadcasting and more specifically in the field of broadcast content customization.
2. Related Art
Prior art communications can be categorized by the degree to which the communication is symmetric. A symmetric communication model allows each party to the communication to transmit and receive with approximately equal ability. For example, a connection between two cell phones is symmetric because each party technically has an equal ability to send and receive. An asymmetric communication is one in which one party does most of the transmitting and the other party does most of the receiving. For example, prior art television broadcasts are asymmetric because one party does most of the broadcasting and (many) other parties do most of the receiving. Some communication models are neither purely symmetric nor asymmetric. For example, pay per view television involves a party making a request over a telephone line. This request is a symmetric communication. If the request is successful, then the requestor may receive keys to decrypt an asymmetric broadcast of a television program.
Typically, a high degree of symmetry is required in communication where parties transmit data specifically intended for each other, or where users can actively request individually customized content. Examples of highly symmetric communication include user initiated web content serving, person-to-person telephony (whether digital or analog), and conference calls (whether physically transmitted on the Internet, the PSTN, or some combination of transport technologies). In such highly symmetric communication models, feedback amongst parties to a given communication is typically rapid, and allows for frequent and/or more specific customization of content transmitted between (and/or among) the parties.
In contrast, a highly asymmetric communication, such as satellite, cable, or internet broadcasting systems, allows little feedback between parties to the communication and customization of content is more difficult because these communications are often unidirectional. Where given content is consumable by a large number of parties, such as in satellite television or XM radio, asymmetric communication is usually preferred. Asymmetric communications make more effective use of bandwidth and mean that a transmitter does not also have to have substantial receiving capability. However, the prior art lacks an efficient method for providing customization in highly asymmetric communications involving many receivers.